1. Field of the Invention
The invention relates to a method of placing a decorative layer on a carrier panel.
2. Description of the Prior Art
The use of decorative foils on so-called polyolefin/wood dust panels, i.e., stiff panels consisting of a polyolefin binder and a wood dust filler is known. Particularly, polyvinyl chloride foils are used as the decorative foils. The foils are attached to the panel using an adhesion mediator which is initially applied on the polyolefin/wood dust panel and the polyvinyl chloride foil. A laminate is formed by heating the polyolefin/wood dust panel and placing it on the lower part of a press. The polyvinyl chloride foil is placed on the panel with its adhesive layer facing the adhesive layer of the panel. The upper press members are then brought together and lamination of the polyvinyl chloride foil with the polyolefin/wood dust panel is effected. Simultaneously, a three-dimensional deformation of the polyolefin/wood dust panel is carried out.
This method has various disadvantages. The polyvinylchloride foil is not permeable to air and gas so that during the compression molding of the composite of the polyolefin/wood dust panel and the polyvinyl chloride foil, air and gas inclusions frequently occur which negatively affect the appearance of the surface of the finished product. To avoid the air and gas inclusions, the polyvinyl chloride foils have been provided with microperforations, so that gas or air can escape through the foil. However, in many cases, such microperforations are undesirable for aesthetic reasons.
In the preparation of thermoplastic foils, and particularly, polyvinyl chloride foils, the foils are often subjected to stretching orientation and thus stress is locked into the material. As a result, the coating of polyolefin/wood dust panels with thermoplastic foils and particularly, polyvinyl chloride foils, has the additional disadvantage that these latent stresses are released and lead to a separation from the carrier panel. This can happen when the polyvinyl chloride foil is later subjected to the influence of heat during use. A typical example would be heat from the sun's radiation when such coated components are used as lining components inside a motor vehicle. This particular danger also exists if a three-dimensional deformation is performed by compression molding of the polyvinyl chloride foil and the polyolefin/wood dust panel. In this case, the separations begin at those locations in which the polyvinyl chloride foil bears against a concavely curved surface region of the polyolefin/wood dust panel.